In a cataract operation, a surgical operation called phacoemulsification is generally performed in order to remove a cloudy crystalline lens of a patient. This operative procedure inserts a dedicated tip into the crystalline lens, vibrates the tip with an ultrasonic wave while supplying a perfusion fluid to crush and emulsify the crystalline lens, and sucks and eliminates the crushed and emulsified crystalline lens together with the perfusion fluid to the outside of a body via a suction passage in the tip.
As a publicly-known tip for phacoemulsification (also referred to simply as a “tip”), for example, structures disclosed in Patent Documents 1 and 2 are proposed.
However, the tip is demanded to be further improved in performance (increased in crushing force and improved in crushing efficiency) and has room for improvement.